Information recording discs made of plastics to perform storing and reading of information by converging rays of light such as laser beam and the like on recording medium containing layers have been widely known, in which disc substrates each having a recording medium containing layer are laminated directly or via spacers with adhesives or by means of ultrasonic welding technique so that said layers face to each other. In such information recording discs, however, the laminated disc substrates are liable to come away from each other by exposure to temperature and moisture cycle employed during long-term service of the discs, and especially those laminated with spacers tend to come away from each other, starting from the inner peripheral side thereof, to which driving force is applied.
With view of obviating such problems as mentioned above, there have been proposed information recording disc reinforced by forming layers of cured resin (adhesive) on the edge surfaces of center holes of the laminated disc substrates (Japanese Patent Laid-open Publin. No. 175046/1984), and information recording discs in which the peripheral portion of the center hole of the laminated disc substrates are provided with holes annually perforated, cage-like connecting rods are inserted into the holes thus perforated, and metallic suction caps are fixed to both the upper and lower parts of the connecting rods thus inserted (Japanese Patent Laid-open Publin. No. 119747/1987).
In the information recording discs referred to above, however, there were involved such problems as will be mentioned below. That is, the former discs are weak in mechanical resistance to driving force from the inner peripheral portion, though are effective in resistance to the temperature and moisture cycle to which they are exposed, and the latter discs are much complicated in structure, require perforating operation and machine therefor when the laminated disc substrates are provided with the connecting rods, and involve difficulty in operation of inserting the connecting rods into the perforated disc substrates and fixing the metallic suction caps thereto.